A patient has been identified with absent liver activity of the enzyme that forms S-adenosylmethionine (MAT). We wish to study this patient to determine whether blood choline and milk choline concentration is low at fasting and whether it responds to dietary supplementation with phosphatidylchoine pills. We also wish to determine whether this patient has fatty liver, which occurs as a side effect of choline deficiency in patients fed a choline deficient diet.